1. Field of the Invention
This invention relates to lubricant additives and compositions thereof and, more particularly, to lubricant compositions comprising oils of lubricating viscosity or greases prepared therefrom containing a minor friction reducing amount, of a borated glycerol hydroxy-ester.
2. Background of the Related
Many means have been employed to reduce overall friction in modern internal combustion engines, particularly automobile engines. The primary reasons are to reduce engine wear thereby prolonging engine life and to reduce the amount of fuel consumed by the engine thereby reducing the engine's energy requirements or fuel consumption.
Many of the solutions to reducing fuel consumption have been strictly mechanical, as for example, setting the engines for a leaner burn or building smaller cars and smaller engines. However, considerable work has been done with lubricating oils, mineral and synthetic, to enhance their friction properties by modifying them with friction reducing additives.
Glycerol hydroxyesters may be used for their friction reducing properties when added to lubricant fluids. However, glycerol hydroxyesters do not adequately control bearing corrosion when used in automotive engine oil lubricants possibly because of their reactive OH groups. Borated glycerol hydroxyesters and borated sulfur containing hydroxyesters provide better friction reduction than their unborated counterparts and, in addition, reduce bearing corrosion to minimal, acceptable levels. The borated glycerol esters of the present invention to the best of applicants' knowledge and belief are novel and have not been used as friction reducing additives or as anti-corrosion or antioxidant additives in lubricating compositions.